Azo compounds are useful as dyes, pigments, carrier generation materials and the like, and a large number of such compounds have been provided for many years. Particularly in recent years, many compound suitable for OPC have been developed. For example, a highly sensitive and highly durable carrier generation material which uses a hydroxynaphthalenedicarboxyimide as a coupler has been proposed in Japanese Patent Publication No. 95-234530 A. The imide proposed in this Patent Publication is 2-hydroxynaphthalene-4,5-dicarboxyimide.